ANA
Antinuclear Antibodies
What this test measures
ANA are antibodies that attack your own cells. They're used to help diagnose autoimmune conditions like lupus (SLE), but can be positive in healthy people too.
Understanding the numbers
Typical range: Negative (or titre less than 1:40)
Up to 15% of healthy people have a low positive ANA. The pattern and titre (strength) help determine significance.
- Negative / background: 0–40 titre
- Low positive: 40–80 titre
- Clinically meaningful: 80–320 titre
- High titre: 320–1280 titre
Key numbers
- 80 titre — Often considered clinically meaningful
- 160 titre — Commonly positive in autoimmune disease
ANA is a screening test. Low-titre positivity (1:40-1:80) is found in 5-15% of healthy people. Higher titres and specific patterns (homogeneous, speckled, nucleolar) plus specific antibodies (anti-dsDNA, anti-Sm, anti-Ro, anti-La, anti-centromere, anti-Scl-70) help identify the specific autoimmune condition. A negative ANA makes SLE very unlikely.
Ranges can vary slightly between laboratories — your report may show slightly different numbers. This page does not read or interpret your result; your GP looks at it alongside your history and other tests.
What a positive result can mean
- May indicate an autoimmune condition like lupus or Sjögren's syndrome
- Higher titres (e.g., 1:160 or above) are more significant
- The pattern of ANA can suggest specific conditions
- Must be interpreted alongside your symptoms
Questions you could ask your GP
- Does this positive ANA mean I have an autoimmune disease?
- Do I need more specific antibody tests?
- Should I be referred to a rheumatologist?
- What symptoms should I watch out for?
Example stories
These are made-up examples to show how results are talked about in real appointments. They are not real patients.
Lupus (SLE) — high-titre ANA with anti-dsDNA
Sarah had butterfly rash on her cheeks, joint pains, mouth ulcers, and hair loss. ANA 1:640 speckled, anti-dsDNA positive, low C3/C4, proteinuria.
What the GP said: “The combination of symptoms and antibodies is classic for SLE — lupus. I'm referring urgently to rheumatology and nephrology, and we'll start treatment while you're assessed.”
What happened next: She was started on hydroxychloroquine and then mycophenolate for lupus nephritis. Remission was achieved within 6 months.
A high-titre ANA with specific autoantibodies (anti-dsDNA, anti-Sm) and typical symptoms supports SLE. Early recognition and treatment — especially when kidneys are involved — significantly improves outcomes.
Weakly positive ANA — no disease
Olivia had vague fatigue. ANA was 1:40 speckled. No other antibodies, normal inflammatory markers, no rash or joint signs.
What the GP said: “A low-titre positive ANA is found in up to 15% of healthy people. With no other clinical features or abnormalities, this is very unlikely to mean autoimmune disease. We'll review if new symptoms appear.”
A low-positive ANA in the absence of clinical features or other autoantibodies is usually not significant. Repeat testing and escalating workups for isolated low-titre ANA often causes more anxiety than benefit.
Systemic sclerosis — specific antibody pattern
Carol had Raynaud's, thickening skin on her fingers, and reflux. ANA 1:320 nucleolar, anti-Scl-70 positive.
What the GP said: “This pattern fits systemic sclerosis. I'll refer you to rheumatology, who will assess for internal organ involvement — especially lung and kidney — and plan monitoring and treatment.”
What happened next: She was assessed and placed on regular lung function monitoring and started on calcium channel blockers for Raynaud's.
Specific ANA patterns and antibodies (nucleolar with anti-Scl-70) point to systemic sclerosis. Regular monitoring for pulmonary hypertension and interstitial lung disease is essential — early detection allows effective treatment.
Primary biliary cholangitis — AMA positive, ANA negative
Dolores had itching and fatigue. ANA was negative. Anti-mitochondrial antibody was strongly positive; ALP was raised.
What the GP said: “A negative ANA doesn't rule out all autoimmune conditions. Your positive AMA and raised ALP point to primary biliary cholangitis — a different autoimmune liver condition. We'll start treatment and refer to hepatology.”
What happened next: Ursodeoxycholic acid was started; itching and ALP improved within months.
A negative ANA rules out SLE very well, but not all autoimmune conditions — AMA-associated primary biliary cholangitis is one example. Matching the right test to the right clinical picture matters.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.